The Chiefs are confident they have the depth to cope with the absence of injured lock Brodie Retallick, who is set to miss up to four weeks of Super Rugby.

Retallick is in the Chiefs’ travel party for the clash against the Rebels in Melbourne on Saturday night.

But the 2014 international player of the year won’t be playing because of a left shoulder injury picked up in the 35-27 win over the Western Force last Friday.

Retallick, 23, missed five weeks earlier in the season because of a problem to his right shoulder.

Coach Dave Rennie says the 36-Test All Black reported during the Force game that his left shoulder felt sore and he was taken off as a precaution.

He had a scan, which showed up a small tear.

Retallick’s unavailability means Michael Fitzgerald comes in to partner Matt Symons against the Rebels.

Rennie said losing Retallick was obviously disappointing, but added that the Chiefs had good depth at lock.

“We’ve played a lot of footy without Brodie this year,” he said.

“We’ve got Fitzy, Matt Symons and Michael Allardice, so we’re pretty well off and we need those boys to front again for us.”

In all, there are six changes to the starting 15, including the return of skipper Liam Messam after a week’s break as part of the All Blacks rest programme.

At first five-eighth, utility Andrew Horrell takes over from Marty McKenzie, who got first go in the No.10 jersey last week after All Black Aaron Cruden’s season-ending knee injury.

Rennie was happy with McKenzie’s performance against the Force but said the coaching staff were still working through the best option at No.10.

He said McKenzie and younger brother Damian McKenzie had each had an opportunity as starting first-five this season.

“We’re pretty keen for Andrew to have a crack,” he said.

The Chiefs are fourth on the overall table, but are just one point behind competition leaders the Hurricanes in the New Zealand conference.

The Rebels, who were pipped 18-16 by defending champions the Waratahs last weekend, are 11th, eight points outside the top six.

Chiefs: Tom Marshall, Tim Nanai-Williams, Charlie Ngatai, Sonny Bill Williams, James Lowe, Andrew Horrell, Brad Weber, Michael Leitch, Sam Cane, Liam Messam (capt), Michael Fitzgerald, Matt Symons, Ben Tameifuna, Hika Elliot, Pauliasi Manu.

Reserves: Quentin MacDonald, Siate Tokolahi, Jamie Mackintosh, Michael Allardice, Johan Bardoul, Augustine Pulu, Damian McKenzie, Bryce Heem.